1. Technical Field
The present invention relates to controlling oscillator signals. In particular, the invention relates to oscillator signals for a wide range of frequencies.
2. Background Information
For microprocessor applications, oscillator circuits are required for providing a time-standard or clock pulse signal. The oscillator circuits fulfill requirements for limiting the power consumption of microprocessors by reducing the frequency during low processor demand, for reducing phase fluctuations between the triggering signals and the clock pulse signal, and minimizing harmonic distortions of the oscillator signal. In each case, amplitude regulation of the oscillator signal is provided.
For example, U.S. Pat. No. 6,570,443 discloses a circuit arrangement for regulating the amplitude of an oscillator signal by comparing the oscillator signal with a reference signal and controlling the amplitude of the oscillator signal with a control signal. The control signal serves to adjust and set an amplitude of the oscillator signal generated by an oscillator circuit.
The problem with conventional amplitude regulation is that the characteristic properties for a regulating circuit are fixed and can only be optimized for a specific oscillator circuit and a specific frequency range. This presents a problem if the oscillator circuit is replaced with an external or internal replacement circuit to provide a different operating frequency.